Process for the oxidation of olefins using catalysts contaning antimony

ABSTRACT

The present invention is a process for the oxidation of olefins to unsaturated aldehydes and acids using a catalyst containing antimony, iron, bismuth, molybdenum plus at least one of nickel, cobalt, magnesium, zinc, cadmium or calcium within certain compositional limits. These catalysts may also contain certain elements that further enhance the desirability of the oxidation process.

This is a continuation of co-pending application Ser. No. 861,490 filedon Dec. 19, 1977, now abandoned, which is a continuation of Ser. No.494,574 filed on Aug. 5, 1974, now abandoned.

SUMMARY OF THE INVENTION

The invention is in the process for the oxidation of propylene orisobutylene to produce the corresponding unsaturated aldehydes and acidsby contacting the propylene or isobutylene with molecular oxygen in thepresence of a catalyst at a temperature of about 200° to about 600° C.,the improvement comprising using as the catalyst a catalyst of theformula

    Sb.sub.a A.sub.b D.sub.c E.sub.d Fe.sub.f Bi.sub.g Mo.sub.12 O.sub.x

wherein

A is an alkali metal, thallium or mixture thereof;

D is nickel, cobalt, magnesium, manganese, strontium, calcium, zinc,cadmium or mixture thereof;

E is phosphorus, arsenic, boron, tungsten or mixture thereof;

and wherein

a is greater than 0 but less than 5;

b and d are 0-4;

c is 0.1 to 20;

f and g are 0.1 to 10; and

X is the number of oxygens required to satisfy the valence requirementsof the other elements present.

This oxidation reaction gives especially desirable results atatmospheric or superatmospheric pressure and especially desirableresults in the oxidation of isobutylene.

The central aspect of the present invention is the particular catalystemployed. The catalysts may be any of the catalysts delimited by theformula described above. Preferred as far as the broad compositionalstructure of the catalyst is concerned are those catalysts that containpotassium, rubidium, cesium or mixture thereof and those catalysts thatcontain nickel, cobalt or mixture thereof.

The catalysts of the invention are prepared by techniques that arebroadly known in the art. These techniques include the coprecipitationof soluble salts. More specific information on the preparation of thecatalysts is given in the Specific Embodiments.

The catalysts of the invention may be used in the supported orunsupported form. Suitable support materials include silica, alumina,Alundum, titania, zirconia, silicon carbide and the like. The catalystsmay also be used in various physical forms. The catalysts can beemployed in a fixed-bed reactor or a fluid-bed reactor.

The process for oxidation of propylene or isobutylene is well known inthe art. Broadly, a mixture of the olefin and molecular oxygen,optionally in the presence of steam or other diluent, is contacted witha catalyst at an elevated temperature of about 200°-600° C. for acontact time sufficient to convert the olefin to the correspondingunsaturated aldehyde and acid. Normally, the product from thesereactions contains a very large portion of the aldehyde and a smallerby-product amount of the unsaturated acid. The contact time may varywidely from a few seconds to a number of seconds or more. The reactioncan be conducted under atmospheric, superatmospheric or subatmosphericpressure with the use of a superatmospheric pressure normally being usedon a commercial scale.

One special advantage of the catalysts of the invention is their abilityto withstand the feed of large amounts of olefin over the catalyst in agiven time. This is normally measured in terms of WWH which is theweight of olefin per weight of catalyst per hour. In other words, thesecatalysts can efficiently work on large amounts of olefin.

SPECIFIC EMBODIMENTS

Various catalysts of the invention were prepared as shown below. Allcatalysts contained 20% SiO₂.

EXAMPLE 1 Sb₀.5 K₀.1 Ni₂.5 Co₄.5 Fe₃ BiMo₁₂ O_(x)

A slurry of 63.56 g. (NH₄)₆ Mo₇ O₂₄.4H₂ O, 61.79 g. of Nalco 34% silicasol and 2.19 g. Sb₂ O₃ was prepared and combined with a solution of36.36 g. Fe(NO₃)₃.9H₂ O, 14.55 g. Bi(NO₃)₃.5H₂ O, 39.29 g. Co(NO₃)₂.6H₂O, 21.80 g. Ni(NO₃)₂.6H₂ O and 3.03 g. of a 10% solution of KNO₃. Themixture was evaporated, dried, heat treated at 290° C. for three hours,425° C. for three hours and 550° C. for 16 hours.

EXAMPLE 2 SbK₀.1 Cu₀.1 Ni₂.5 Co₄.5 Fe₃ BiMo₁₂ O_(x)

This catalyst was prepared in essentially the same way as shown inExample 1 but copper was added in the form of Cu(NO₃)₂.3H₂ O.

EXAMPLES 3 AND 5 Sb₀.5 Cs₀.5 Ni₂.5 Co₄.5 Fe₃ BiMo₁₂ O_(x)

This catalyst was prepared in essentially the same manner as Example 1,except that CsNO₃ replaced the potassium compound.

EXAMPLES 4 AND 7 Sb₁.0 Cs₀.5 S₀.25 Ni₂.5 Co₄.5 Fe₃ BiMo₁₂ O_(x)

The catalyst was prepared in the same manner as described above exceptthat Cs₂ SO₄ was employed to incorporate sulfur in the catalyst.

EXAMPLE 6 Sb₀.5 Cs₀.2 Ni₂.5 Co₄.5 Fe₃ BiMo₁₂ O_(x)

The catalyst was prepared in the same manner as shown in Example 1,except that CsNO₃ was employed rather than the potassium.

In a fixed-bed reactor constructed of a 0.75 cm. inside diameterstainless steel tube was placed 5 cc. of each catalyst prepared above.The catalysts were tested at a temperature of 371° C. using a feed ofisobutylene/air/steam of 1/10/4 and an apparent contact time of 3.7±0.4seconds.

The results of these experiments are given in the Table.

The results are stated as follows: ##EQU1## In the Table MA ismethacrolein and MAA is methacrylic acid.

                  TABLE                                                           ______________________________________                                        Oxidation of Isobutylene to Methacrolein                                      and Methacrylic Acid Using a Catalyst of                                      YNi.sub.2.5 Co.sub.4.5 Fe.sub.3 BiMo.sub.12 O.sub.x                                     Results, %                                                          Ex-             Yield Per Pass   Con-  Select-                                ample                                                                              Catalyst Y=                                                                              MA      MMA    Total version                                                                             ivity                              ______________________________________                                        1    Sb.sub.0.5 K.sub.0.1                                                                     60.8    4.9    65.7  100.0 65.7                               2    Sb.sub.0.5 K.sub.0.1 Cu.sub.0.1                                                          66.1    1.4    67.5  100.0 67.5                               3    Sb.sub.0.5 Cs.sub.0.5                                                                    80.3    3.3    83.6   99.4 84.2                               4    Sb.sub.1.0 Cs.sub.0.5 S.sub.0.25                                                         74.1    1.0    75.1   82.1 91.4                                .sup. 5.sup.a.                                                                    Sb.sub.0.5 Cs.sub.0.5                                                                    61.1    8.5    69.6   98.8 70.5                                .sup. 6.sup.a.                                                                    Sb.sub.0.5 Cs.sub.0.2                                                                    66.1    5.3    71.4  100.0 71.4                                .sup. 7.sup.b.                                                                    Sb.sub.1.0 Cs.sub.0.5 S.sub.0.25                                                         77.2    1.6    78.8   92.8 85.0                               ______________________________________                                         .sup.a. pressure 12 p.s.i.g.                                                  .sup.b. pressure 9.7 p.s.i.g.                                            

EXAMPLE 8 Preparation of acrolein and acrylic acid

In the same manner as described in the examples above, a catalyst ofSb₀.5 K₀.1 Ni₂.5 Co₄.5 Fe₃ BiMo₁₂ O_(x) was prepared and used in theoxidation of propylene. The catalyst was placed in a 5 cc. reaction zoneof a reactor constructed of a stainless steel tube. The temperature ofthe reaction zone was maintained at 380° C. and the apparent contacttime was three seconds. A feed of propylene/air/steam of 1/11/4 wasemployed. Of the propylene fed, 96.8% was converted with a selectivityto acrolein and acrylic acid of 94.9%. The yield per pass of acroleinwas 78.1%, the yield per pass of acrylic acid was 13.8% and the totalyield per pass to acrolein and acrylic acid was 91.9%.

We claim:
 1. A process for the oxidation of isobutylene to produce thecorresponding unsaturated aldehyde by contacting isobutylene withmolecular oxygen in the presence of a catalyst having the composition:

    L.sub.a Fe.sub.b Bi.sub.c B.sub.d Sb.sub.e J.sub.g Mo.sub.h O.sub.i

in which L is a mixture of cobalt and nickel, J represents at least oneelement selected from the group consisting of potassium, rubidium andcesium, a, b, c, d, e, g, h, and i represent the numbers of L, iron,bismuth, boron, antimony, J, molybdenum and oxygen atoms, respectively,with the proviso that the elements are present in a ratio so that when his 12, a is 0.1 to 20, b is 0.1 to 10, c is 0.1 to 10, d is greater thanzero and less than or equal to 4, e is greater than zero but less than5, g is greater than zero and less than or equal to 4 and i is thenumber of oxygens required to satisfy the valence requirements of theother elements present.
 2. A process for the oxidation of isobutylene toproduce the corresponding unsaturated aldehyde by contacting isobutylenewith molecular oxygen in the presence of a catalyst having thecomposition:

    L.sub.a Fe.sub.b Bi.sub.c B.sub.d Sb.sub.e J.sub.g Mo.sub.h O.sub.i

in which L is cobalt or a mixture of cobalt and nickel, J represents atleast one element selected from the group consisting of potassium,rubidium and cesium, a, b, c, d, e, g, h, and i represent the numbers ofL, iron, bismuth, boron, antimony, J, molybdenum and oxygen atoms,respectively, with the proviso that the elements are present in a ratioso that when h is 12, a is 0.1 to 20, b is 0.1 to 10, c is 0.1 to 10, dis greater than zero and less than or equal to 4, e is greater than zerobut less than 5, g is greater than zero and less than or equal to 4 andi is the number of oxygens required to satisfy the valence requirementsof the other elements present.
 3. The process of claim 2 wherein h is12, a is 3 to 12, b is 0.5 to 3, c is 0.5 to 4, d is 0.5 to 3, e is 0.05to 1, f is 0 to 3, g is 0.01 to 0.5 and i is 42 to
 77. 4. The process ofclaim 2 wherein the reaction is carried out in the presence of steam. 5.The process of claim 2 wherein the reactant is isobutylene.
 6. Anoxidation catalyst having the composition

    L.sub.a Fe.sub.b Bi.sub.c B.sub.d Sb.sub.e J.sub.g Mo.sub.n O.sub.i

in which L is cobalt, or a mixture of cobalt and nickel, J represents atleast one element selected from the group consisting of potassium,rubidium and cesium, a, b, c, d, e, g, h, and i represent the numbers ofL, iron, bismuth, boron, antimony, J, molybdenum and oxygen atoms,respectively, with the proviso that the elements are present in a ratioso that when h is 12, a is 0.1 to 20, b is 0.1 to 10, c is 0.1 to 10, dis greater than zero and less than or equal to 4, e is greater than zerobut less than 5, g is greater than zero and less than or equal to 4 andi is the number of oxygens required to satisfy the valence requirementsof the other elements present.
 7. The oxidation catalyst of claim 6wherein the ratio is such that when h is 12, a is 3 to 12, b is 0.5 to5, c is 0.5 to 4, d is 0.5 to 3, e is 0.05 to 1, f is 0 to 3, g is 0.01to 0.05 and i is 42 to 77.